Approximately 68 percent of U.S. adults are overweight or obese, according to the National Cancer Institute, which puts them at greater risk for developing cancer, cardiovascular disease, diabetes and a host of other chronic illnesses. But an international team of scientists led by Virginia Commonwealth University Massey Cancer Center researcher Andrew Larner, M.D., Ph.D., has successfully reversed obesity in mice by manipulating the production of an enzyme known as tyrosine-protein kinase-2 (Tyk2). In their experiments, the scientists discovered that Tyk2 helps regulate obesity in mice and humans through the differentiation of a type of fat tissue known as brown adipose tissue (BAT).